Sum matrix elements group by indices in Python

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  import os
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      while (h <= m && k <= n)
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          {
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          }
  
          if (mat[i_max][k] == 0)
          {
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          auto temp = mat[h];
          mat[h] = mat[i_max];
          mat[i_max] = temp;
  
          for (auto j = h + 1; j <= m; ++j)
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              for (auto v = k + 1; v <= n; ++v)
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              }
          }
  
          ++h;
          ++k;
      }
  }
  
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      return 0;
  }
  

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  This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information.

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  I'm trying to plot a lift curve using the defined function below:

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